Method and device for controlling combined UMTS/GSM/EDGE radio systems

ABSTRACT

In a method for controlling radio systems designed for transmission/reception of signals based on at least two radio standards with different time patterns, with signals based on one of these radio standards being processed in each radio system, at least one synchronization signal is produced in the first and/or second radio system for synchronization, respectively, is transmitted to the respective other radio system and system information associated with that particular radio system is in each case stored in that radio system to which the synchronization signal is transmitted. The stored system information can be read by the respective other radio system via an interface, and times for transmission of signals can be calculated by means of the information which has been read. The transmission of signals or the production of events in a radio system can be enabled or inhibited by means of a signal from the other radio systems.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/993,337 filed Nov. 19, 2004 now U.S. Pat. No. 7,089,025, which is acontinuation of copending International Application No. PCT/DE03/01555filed May 14, 2003 which designates the United States, and claimspriority to German application no. 102 24 798.6 filed Jun. 4, 2002.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a method for controlling radio systems in aradio station, in particular a mobile radio station, with the radiostation being designed for transmission/reception of signals based on atleast two radio standards with different time patterns. The inventionfurthermore relates to an apparatus for controlling radio systems in aradio station.

DESCRIPTION OF RELATED ART AND BACKGROUND OF THE INVENTION

A large number of actions have to be initiated and control signalsproduced in transmitting and receiving devices in mobile stations, andthese are correlated in time with a special time pattern, which isspecific to the mobile radio standard.

A number of different standards have become established in the mobileradio field in recent years, and have been developed further or will bereplaced by new standards in the future. Known examples of mobile radiostandards are GSM (Global System for Mobile Communication), the 8 PSK(8-Phase Shift Keying) further development of GSM which is referred toas the EDGE (Enhanced Data Services for GSM Evolution) Standard, andvarious standards based on the CDMA (Code Division Multiple Access)transmission method such as UMTS (Universal Mobile TelecommunicationSystem). Another radio standard for the fourth generation is currentlyalready being developed as the MBS (Mobile Broadband System).

The requirements for mobile stations for mobile radio are growing withthe presence of different and competing standards. Mobile stations whichcan support two or more mobile radio systems or standards at the sametime are desired. This is dependent on the mobile station being able toproduce the different time patterns for the individual standards, andbeing able to carry out suitable event control processes based on them.

The transmission methods, for example CDMA and TDMA, for these twodifferent mobile radio standards are based on different symbol clockfrequencies, with the transmitted data normally being structured intransmission frames, which each have a predetermined length. Thisstructure and/or length of each transmission frame in a continuoussignal sequence is predetermined, and is identified by the mobilestation. The mobile station has to align its time sequence control tothis structure. One difficulty that occurs in this case is thatdifferent mobile radio standards use generally incommensurable timepatterns, that is to say the time patterns can generally not be changedto one another by simple clock division. Particularly in cellular mobileradio systems, the mobile station also has to carry out furtherfunctions other than the transmission and reception of data, whichcannot be carried out at the same time, at least during operation ofonly a single receiving device. By way of example, a mobile stationwhich supports two or more mobile radio standards, in a cellular radiocommunications system in which the base stations in different cellstransmit at different frequencies has to measure, from time to time,whether it can receive radio signals from a different base station withsufficient reception quality. To do this, the mobile station sets itsreceiving device to a different frequency than that frequency at whichit is currently receiving data. The data is in this case sent, forexample using a UMTS system, from a base station to a receiving mobilestation by interrupting the transmission at predetermined times suchthat it is possible for the receiving mobile station to carry out otherfunctions, such as an adjacent channel search (search for specific datapackets which are transmitted from an adjacent base station) during oneor more interruption phases and, in particular, also to carry outmeasurements. In order to avoid loss of data, the base station transmitsits data in advance at a higher transmission rate than the generallyconstant continuous transmission rate. In order that this increasedtransmission rate does not lead to higher bit error rates, thetransmission power is also increased during this time period in whichdata is being transmitted at an increased transmission rate.

The frequency with which interruption phases are repeated as well as thetime duration of the interruption phases depend on the respective radiosystem, and also on the respective operating mode of this radio system.One disadvantage in this case is that, as the number of insertedinterruption phases increases, the transmission power on the one handbecomes higher, and the transmission quality on the other handdeteriorates.

SUMMARY OF THE INVENTION

The object of the invention is to provide a method and an apparatus forcontrolling radio systems in a radio station, by means of which theeffort for synchronization to different time patterns can be minimized.

In a method according to the invention for controlling radio systems ina radio station, in particular a mobile radio station, the radio stationsupports at least two radio standards with different time patterns.Signals for one radio standard are processed in each of the radiosystems. At least one synchronization signal is in each case produced inthe first and/or second radio system, and the synchronization signal istransmitted to the respective other radio system. The system informationfor synchronization of the radio systems for that particular system isin each case stored in that radio system to which the synchronizationsignal is transmitted from the other radio system.

It is advantageous for the time at which the storage of systeminformation in one of the radio systems starts to be determined by theother radio system by means of the synchronization signal. The storageof system information in the other radio system can in this way beinitiated accurately at defined times in the first radio system.

In one preferred exemplary embodiment, the synchronization signal whichis produced by one radio system is passed to a control unit, inparticular a time control unit, in the other radio system, and thesystem information is stored in a memory unit in this control unit. Thesynchronization signals for each radio system are advantageouslyproduced in a respective signal generator, in particular asynchronization signal generator. This signal generator and theproduction of the synchronization signal in a radio system arepreferably controlled by the control unit which is associated with thisradio system. This means that the radio systems, in particular therespective control units, can be synchronized quickly and in a simplemanner.

In one particularly preferred exemplary embodiment, the systeminformation (which is stored in the second radio system at a time whichis predetermined by the first radio system) for the second radio systemis read by the first radio system, and times for interchanging databetween the radio station and other stations can advantageously bedetermined from signals from the first radio system by means of thissystem information, which has been read from the second radio system, inthe first radio system. This means that a radio system transmissionphase which is characterized by the system information can be checked bythe other radio system at times defined by this other radio system. Thestart and/or the end of an interruption phase in the radio system beingchecked can thus be determined by the checking radio system.

The frame number of the transmission frame for transmission of dataand/or a number of a time slot which is allocated to a transmissionframe and/or the number of a unit into which a time slot is subdividedare/is advantageously stored as system information.

In one advantageous exemplary embodiment, a second synchronizationsignal is in each case produced in the first and/or in the second radiosystem. This second synchronization signal is passed to the respectiveother radio system, and the transmission of radio signals or theproduction of events in the radio system to which the secondsynchronization signal is passed is enabled or inhibited in thisrespective other radio system at a time which can be predetermined bythe applied second synchronization signal in the radio system whichproduces this second synchronization signal. This makes it possible toachieve optimum frequency control of synchronization processes andoptimum event control for the radio systems. This makes it possible toprevent both radio systems from transmitting signals at the same time.

It is advantageous if the second synchronization signals are produced inthe respective signal generators in the radio systems, and are passed tothe signal generators in the respective other system. It is alsopossible to provide for the first and second synchronization signal in aradio system to be combined to form a simple synchronization signal, andfor the information for synchronization on the information for enablingor inhibiting a transmission process to be coded. This means that theinitiation of a storage process for system information and the enablingor inhibiting of a transmission process in a radio system at the sametime can be controlled by the other radio system by means of a singlesignal.

The method is particularly advantageous if the radio station supportsthe two mobile radio standards UMTS and GSM/EDGE.

An apparatus according to the invention for controlling radio systems ina radio station, in particular a mobile radio station, with the radiostation being designed for transmission/reception of signals based on atleast two radio standards with different time patterns, has a firstcontrol unit, in particular a first time control unit and a first signalgenerator, which is connected downstream from this first control unit,in particular a first synchronization signal generator. This firstcontrol unit and this first signal generator are allocated to the firstradio system in order to produce at least one first synchronizationsignal for the first radio system. A second control unit in particular asecond time control unit, and a second signal generator which isconnected downstream from this second control unit, in particular asecond synchronization signal generator, are allocated to the secondradio system in order to produce at least one first synchronizationsignal for the second radio system. The first and the second controlunit each have at least one memory unit. The first signal generator iselectrically connected to the second radio system, and the second signalgenerator is electrically connected to the first radio system. Theapparatus according to the invention allows the radio systems to besynchronized and, if appropriate, the interruption phases in the radiosystems to be minimized in terms of the time duration and the number ofthem.

At least in one radio system, the control unit advantageously has asecond memory unit, in which case system information for the datareception path can be stored in the first memory unit in this controlunit, and system information relating to the data transmission path canbe stored in this second memory unit. This allows the system informationfor the data reception path and for the data transmission path in aradio system to be stored separately.

In one preferred exemplary embodiment, the first signal generator isconnected to the first input of the second signal generator and to thesecond control unit for the second radio system. In particular, in thiscase it has an electrical connection at least to the first memory unitin the second radio system. The second signal generator is electricallyconnected to one input of the first signal generator and to the firstcontrol unit for the first radio system, in particular at least to thefirst memory unit for the first radio system. By means of appropriatecontrol signals, in particular synchronization signals it is thuspossible for the second signal generator to be activated or deactivatedby means of the first signal generator or for the first signal generatorto be activated or deactivated by the second signal generator, or forsystem events in the first radio system to be enabled or inhibited bymeans of the second signal generator, or for system events in the secondradio system to be enabled or inhibited by the first signal generator.

It is advantageous for the radio systems to be connected by means of anelectrical connection, in particularly a synchronous serial interface,via which system information, in particular the contents of the memoryunits in one radio system can be read and evaluated by the other radiosystem. This makes it possible for one radio system to simply determinethe start or the end of an interruption phase in the other radio system.

BRIEF DESCRIPTION OF THE DRAWINGS

One exemplary embodiment of the invention will be explained in moredetail in the following text with reference to schematic drawings, inwhich:

FIG. 1 shows a block diagram of an apparatus according to the invention;

FIG. 2 shows a timing diagram of a process for storing systeminformation; and

FIG. 3 shows a timing diagram for enabling or inhibiting system events.

DETAILED DESCRIPTION OF EMBODIMENTS

The apparatus according to the invention and the method according to theinvention are described in the exemplary embodiment on the basis of amobile station which supports the two mobile radio standards UMTS andGSM/EDGE. The apparatus according to the invention has a UMTS timecontrol unit 1, which is connected to memory units 11 and 12. The UMTStime control unit 1 and the two memory units 11 and 12 are electricallyconnected to the UMTS bus system via an interface SST1. The UMTS timecontrol unit 1 controls a downstream signal generator which, in theexemplary embodiment, is in the form of a synchronization signalgenerator 2. The synchronization signal generator 2 has a unit 21 inwhich events are produced for the UMTS transmission path. The unit 21 iscontrolled by the control signal SA1 from the UMTS time control unit 1.Furthermore, the synchronization signal generator 2 has a unit 22 forproduction of events for the UMTS reception path, which is controlled bya control signal SA2 from the UMTS time control unit 1. Thesynchronization signal generator 2 is electrically connected to the UMTSbus system via an interface SST2. The UMTS time control unit 1, thememory units 11 and 12 and the synchronization signal generator 2,together with its units 21 and 22, are associated with the UMTS radiosystem.

Furthermore, the apparatus has a GSM time control unit 3 which isconnected to a memory unit 31. The GSM time control unit 3 and thememory unit 31 are electrically connected to the GSM bus system via aninterface SST3. The apparatus has a second signal generator which, inthe exemplary embodiment, is in the form of a synchronization signalgenerator 4 with a unit 41 for production of the events for the GSMtransmission path and GSM reception path. The second synchronizationsignal generator 4 is connected to the GSM bus system via an interfaceSST4. The synchronization signal generator 4 or the unit 41 iscontrolled by the GSM time control unit 3 via a control signal SA3. TheGSM transmission path or GSM reception path events which are produced inthe unit 41 are transmitted by means of the signal 411. Thesynchronization signal generator 4 or the unit 41 produces a firstsynchronization signal SY4 a, which is passed to the memory units 11 and12 for the UMTS radio system. The unit 41 produces a secondsynchronization signal SY4 b, which is passed to the units 21 and 22 inthe synchronization signal generator 2 for the UMTS radio system. TheUMTS transmission path events which are produced in the unit 21 aretransmitted via the signal 211. The UMTS reception path events which areproduced by the unit 22 are transmitted by the signal 221. The unit 21produces a first synchronization signal SY2 a for the UMTS radio system,which is passed to the memory unit 31 for the GSM radio system. The unit21 produces a second synchronization signal SY2 b, which is passed toone input of the synchronization signal generator 4 or of the unit 41.

The apparatus furthermore has a synchronous serial connection SSC, bymeans of which the GSM radio system can read the contents of the memoryunits 11 and 12 for the UMTS system, while the UMTS system can read thecontents of the memory unit 31 for the GSM radio system. Systeminformation for the reception path of the UMTS system is stored in thememory unit 11 for the UMTS system, and system information for thetransmission path of the UMTS system is stored in the memory unit 12.System information for the GSM system is stored in the memory unit 31for the GSM system. In the exemplary embodiment, the memory units 11, 12and 31 are illustrated as separate external memory units. It is alsopossible for the memory units 11 and 12 to be arranged in the UMTS timecontrol unit 1, and/or for the memory unit 31 to be arranged in the GSMtime control unit 3.

In the exemplary embodiments, the frame number of the transmission framefor transmission of data Frame_(RX), Frame_(TX), a number of a time slotSlot_(RX), Slot_(TX) which is associated with the correspondingtransmission frame Frame_(RX) or Frame_(TX), respectively, and intowhich a transmission frame is subdivided, as well as the chip numbersChip_(RX), Chip_(TX) into which the time slots Slot_(RX) and Slot_(TX),respectively, are divided, are stored as system information in thememory units 11 and 12 in the UMTS radio system. The frame numberFrame_(GSM) of the data transmission frame, the number of a time slotSlot_(GSM) which is associated with the transmission frame Frame_(GSM)as well as the GSM symbol number Symbol_(GSM) into which the time slotSlot_(GSM) is subdivided are stored as system information for the GSMradio system in the memory unit 31. Passing the first synchronizationsignal SY4 a from the synchronization signal generator 4 to the memoryunits 11 and 12 results in the UMTS system information for the receptionpath and for the transmission path, respectively, being stored in therespective memory units 11 and 12 at a time which is predetermined bythe GSM system. This first synchronization signal SY4 a is generated inthe synchronization signal generator 4 or in the unit 41 at a specificGSM time, which is identified by the system information in the GSMsystem relating to this time. The second synchronization signal SY4 b isgenerated in the unit 41 in the signal generator 4 at the same time, orat a different time, in order to produce the first synchronizationsignal SY4 a. This second synchronization signal SY4 b in the GSM systemis passed to the units 21 and 22 in the signal generator 2 for the UMTSsystem. UMTS events which have been combined in a group and are producedin the units 21 and 22 are enabled or inhibited by means of thissynchronization signal SY4 b. This allows UMTS events to be enabled orinhibited at specific GSM times.

Passing the first synchronization signal SY2 a, which is produced in theunit 21 in the signal generator 2 in the UMTS system, to the memory unit31 results in the GSM system information being stored in the memory unit31 for a specific UMTS time. In consequence, the GSM system informationis stored for a specific UMTS time, which is identified by the systeminformation in the UMTS system relating to this time. The secondsynchronization signal SY2 b is produced by the unit 21 and is passed tothe unit 41 in the synchronization signal generator 4 at the same timeor at a different time in order to produce the first synchronizationsignal SY2 a for the UMTS system. GSM events which have been combined ina group are enabled or inhibited by means of the second synchronizationsignal SY2 b in the UMTS system. Those UMTS events and GSM events whichhave been enabled or inhibited by the synchronization signals SY4 b andSY2 b, respectively, can be combined into groups by respective specialmarkings. Passing the second synchronization signal SY2 b to thesynchronization signal generator 4 in the GSM system allows, forexample, the transmission of signals to be prevented in the GSM system.This ensures that the GSM system cannot transmit signals in aninterruption phase during a measurement of a UMTS base station.

After the completion of a measurement process of a UMTS base station,the transmission of signals in the GSM system can be enabled once againby the synchronization signal SY2 b. This allows GSM events to beenabled or inhibited by the UMTS system at defined UMTS times, withoutthe GSM system needing to know the precise UMTS time, which isidentified by the UMTS system information relating to this time. GSMevents can thus be enabled or inhibited with respect to the UMTStransmission path at specific UMTS times.

These statements relating to the synchronization signal SY2 b also applyin an analogous manner to the synchronization signal SY4 b for the GSMsignal.

It is also possible to provide for the synchronization signals SY2 a andSY2 b for the UMTS system to be combined to form a singlesynchronization signal. The information which is contained in theseparate synchronization signals SY2 a and SY2 b must be coded when asingle synchronization signal is present in the UMTS system. It islikewise possible for the two synchronization signals SY4 a and SY4 bfor the GSM system to be combined to form a single synchronizationsignal, and for the information which is contained in the individualsynchronization signals SY4 a and SY4 b, respectively, to be coded.

FIG. 2 shows a timing diagram for a process for storing the UMTS systeminformation relating to a specific GSM time, as well as a process forstoring GSM system information relating to a specific UMTS time. In thiscase the illustration shows in particular the process of storing theUMTS system information by means of the synchronization signal SY2 a,and for storing the GSM system information by means of thesynchronization signal SY4 a. The timing diagram shown in FIG. 2 showsUMTS/GSM synchronization during a UMTS interruption phase, whose startis identified by the time T₁, and whose end is identified by the timeT₂. The UMTS system information is provided by the frame number of thetransmission frame, the number of the time slot and the number of achip, and is illustrated in the figure by the time slot numbersSlot_(N), Slot_(N+1) to Slot_(N+4) with the correspondingly finersubdivision into chips with 2560 chips per time slot. The GSM systeminformation, which is independent of the UMTS system information and isbased on a different symbol plot frequency, is likewise provided byframe numbers for the transmission frames, the time slot numbers and thesymbol number, and is illustrated in the timing diagram in FIG. 2 bytime slot numbers Slot_(K), Slot_(K+1) to Slot_(K+8), with the likewisecorrespondingly finer subdivision into symbols with 156.25 symbols pertime slot or slot. The synchronization pulse SY2 a illustrates thetransfer of the UMTS system information (frame, time slot and chipnumber) to the memory unit 12 in the UMTS time control unit 1. In acorresponding manner, the synchronization pulse in the synchronizationsignal SY4 a illustrates the transfer or the storage of the GSM systeminformation (frame, time slot and symbol number) in the memory unit 31in the GSM time control unit 3. This means that both the GSM system andthe UMTS system read the system information for the respective othersystem, in particular by means of the serial synchronous connection SSC,and can then calculate this in advance by software. As is shown by wayof example in the timing diagram in FIG. 2, the GSM system can calculatethe time T₂ for the UMTS interruption phase in advance from the UMTSsystem information that is stored for a specific GSM time.

FIG. 3 shows a timing diagram illustrating the method of operation ofUMTS events, which have been combined into groups, by the GSM timecontrol unit 3, and of GSM events by the UMTS time control unit 1. TheUMTS system information and the GSM system information correspond to theinformation in FIG. 2. The synchronization signals SY2 b and SY4 boperate as follows. In the illustrated exemplary embodiment, thesynchronization signal SY2 b enables a group of UMTS events in the GSMSlot_(K) and in the GSM Slot_(K+1). Since the synchronization signal SY2b changes from a low level to a high level, a group of UMTS events fromthe GSM Slot_(K+2) to the GSM Slot_(K+7) is inhibited during the UMTSinterruption phase in the time period between T₁ and T₂. A furtherchange in the level of the synchronization signal SY2 b once againenables this group of UMTS events in the GSM Slot_(K+8). The levelstates of the synchronization signal SY4 b which is illustrated in theexemplary embodiment results in a group of GSM events being inhibitedbefore the time T₁ and after the time T₂. A group of GSM events isenabled from the UMTS Slot_(N+1) to the UMTS Slot_(N+3) during the timeperiod of the UMTS interruption phase.

The apparatus according to the invention and the method according to theinvention allow optimum sequence control of synchronization processesbefore, during and after UMTS/GSM interruption phases in combinedUMTS/GSM mobile stations. For sequence control of synchronizationprocesses and for event control, the UMTS system uses a time controlunit 1 based on UMTS system information, where the GSM system uses atime control unit 3 based on the GSM system information. The respectiveUMTS system information is transmitted to the GSM system, and therespective GSM system information is transmitted in a correspondingmanner to the UMTS system. The UMTS synchronization signals SY2 a, SY2 band the GSM synchronization signals SY4 a, SY4 b respectively, as wellas the memory units 11, 12, 31 allow the GSM system information and theUMTS system information, respectively, to be stored, and the checking ofGSM events and UMTS events, respectively, which have been combined intogroups to be carried out at accurate times, in order to make it possibleto optimally monitor the sequence control of synchronization processesbefore, during and after UMTS/GSM interruption phases. This means thatspecially identified UMTS events (group) can be enabled or inhibited bythe GSM time control unit 3, or specially identified GSM events (group)can be enabled or inhibited by the UMTS time control unit 1.Particularly when the UMTS system and the GSM system are being operatedat the same time, that is to say before, during and after UMTSinterruption phases by the GSM system, and before, during and after GSMinterruption phases by the UMTS system, the GSM system must know theUMTS system information, and the UMTS system must know the GSM systeminformation. This makes it possible to guarantee optimum sequencecontrol of the UMTS and GSM synchronization processes and, for example,to avoid the UMTS system and the GSM system transmitting at the sametime in a combined UMTS/GSM mobile station. The method according to theinvention and the apparatus according to the invention can be usedindependently of the respective symbol clock frequencies and physicalworking clocks that are used in the UMTS system and in the GSM system.

1. A method, comprising: providing first and second signals basedrespectively upon first and second radio standards to a radio stationhaving first and second systems; processing the first signals in a firstsystem, generating a first synchronization signal from the processedfirst signal and providing it to the second system; processing thesecond signals in a second system, generating a second synchronizationsignal from the processed second signal and providing it to the firstsystem; and storing suitable second system information in the firstsystem upon receipt of the second synchronization signal and storingsuitable first system information in the second system upon receipt ofthe first synchronization signal.
 2. A method of providing sequencecontrol of a UMTS system and a GSM system in a combined UMTS/GSM mobilestation, comprising: receiving UMTS/GSM signals based respectively uponUMTS and GSM standards to a station having UMTS and second systems;processing the UMTS signals in a UMTS system, generating a UMTSsynchronization signal from the processed UMTS signal and providing itto the GSM system; processing the second signals in a GSM system,generating a GSM synchronization signal from the processed GSM signaland providing it to the UMTS system; storing suitable GSM systeminformation in the UMTS system upon receipt of the GSM synchronizationsignal and storing suitable UMTS system information in the GSM systemupon receipt of the UMTS synchronization signal; and utilizing thestored GSM system information from the UMTS system and the stored UMTSinformation from the GSM system to inhibit the UMTS and GSM fromtransmitting at the same time.
 3. A radio station configured to processsignals based upon first and second radio standards, comprising: a firstsystem configured to receive a first signal based upon the first radiostandard, and to generate a first synchronization signal for a secondsystem, the first synchronization signal being based on the firstsignal; the second system configured to receive a second signal basedupon the second radio Standard, and to generate a second synchronizationsignal for the first system, the second synchronization signal beingbased on the second signal; and a control unit configured to storesecond system information in the first system in accordance with thesecond synchronization signals, and further configured to store firstsystem information in the second system in accordance with the firstsynchronization signal.
 4. A station configured to process signals basedupon first and second radio standards, comprising: a first systemconfigured to receive a first signal based upon the first standard, andto generate a first synchronization signal for a second system, thefirst synchronization signal being based on the first signal; the secondsystem configured to receive a second signal based upon the secondstandard, and to generate a second synchronization signal for the firstsystem, the second synchronization signal being based on the secondsignal; and a synchronous serial connection coupled to store secondsystem information in the first system in accordance with the secondsynchronization signal, and to store first system information in thesecond system in accordance with the first synchronization signal,wherein one of the first and second systems comprises a time controlunit, and wherein the time control unit is configured to receive systeminformation from the other of the first and second systems to avoidtransmission in that one of the first and second system duringtransmission in the other of the first and second systems.